CBR F3 power output and ignition settings

[Tom Holdstock]

Hi, i'm from the uni surey team in england. I'm working on my own to tune the CBR F3 engine we have decided to use in the competition. It is normally aspirated and has a PE -ltd eCU with an injection rail addition.

Could anyone tell me the power output they have for this engine with the restrictor or afor a similar 600cc normally aspirated 600cc motorbike engine wuning on pump gas.

Also, could anyone tell me the ignition settings they started with as Honda can't give me the ones for the engine i'm using, so far i've been told

1200 rpm 10 degree initial

5500rpm 42 degrees adavce or 8500rpm 29 degrees advance. I';m using the standar FSAE one supplied by PE-ltd so far.

Also, my exhaust collect into a chamber on the dyno, this glows red hot!!! Is it due to all four pistons merging so close after the cylnder head or is the ignition ntoo far retarded or advanced.

Any help is much appreciated... Tom.

[Tom Holdstock]

Hi, i'm from the uni surey team in england. I'm working on my own to tune the CBR F3 engine we have decided to use in the competition. It is normally aspirated and has a PE -ltd eCU with an injection rail addition.

Could anyone tell me the power output they have for this engine with the restrictor or afor a similar 600cc normally aspirated 600cc motorbike engine wuning on pump gas.

Also, could anyone tell me the ignition settings they started with as Honda can't give me the ones for the engine i'm using, so far i've been told

1200 rpm 10 degree initial

5500rpm 42 degrees adavce or 8500rpm 29 degrees advance. I';m using the standar FSAE one supplied by PE-ltd so far.

Also, my exhaust collect into a chamber on the dyno, this glows red hot!!! Is it due to all four pistons merging so close after the cylnder head or is the ignition ntoo far retarded or advanced.

Any help is much appreciated... Tom.

[B Lewis @ PE Engine Management]

Hi Tom,

I don't have any dyno results handy, although I know I have seem them floating around on this forum. Try searching if you haven'y already.

Our base map tends to be very conservative for ignition. Generally, it is a retarded from ideal for most engine combinations. We do that to stay on the safe side of detonation.

Abnormally hot exhaust (ie. glowing red after only a short time at low load) can be caused by ignition that is not advanced enough. Essentially, you are still finishing the combustion process as the exhaust valve opens. This tends to heat the headers up quite a bit. Try advancing the curve and see if that helps. The Honda engines are very forgiving and without forced induction are virtually bulletproof.

Good luck.

[Tom Holdstock]

cheers brian, I was thinkign that too. I'm tryniug different AFr's to get the max power for each RPM and load at the moment. I'll advvance it a bit at a time. The honda manual says 42 degrees from 5500 but this seems a little strange having a flat curve from that low a rev range..

[Dallas Blake]

Here are some numbers from out current map.

32 degrees at 5000RPM 101KPA
40 degrees at 8600RPM 101KPA
45 degrees at 11500RPM 101KPA

We use speed density mapping and for a speed density mapping you need much more advance at lower manifold pressures, much more advance than you would expect. For Example, at 40KPA 4000RPM we are around 36 degrees

Every engine power output will be different depending on your tuning, intake, exhaust, fuel injection, etc. But as a general rule of thumb, 65HP can be had quite easily, 75 with some work, 80 if your quite skilled, 55 if your a rookie or your dyno data is incorrect(AFR, egt etc)

[Tom Holdstock]

cheers, dallas

Thats apporx 10 degrees more on each than i'm using... I'll put those numbers in or iterate up to them and see what I get...

I'm on 51hp witha 14.7afr and around 35 ilft torque but i expect these to go up with an increased fuel ratio... i'm iterating the air fule ratio to get the optimum power. The main problem is the header i have on the rig, oit collets just after the head and restricts the flow a bit... there'll be a 4-2-1 for the cmop which will increase the power too.

Check the heat on this:

http://i70.photobucket.com/albums/i119/moscoworbust/DSC00738.jpg

[Dallas Blake]

Tom,

That AFR seems mighty high, Are you using a wideband? Where is it located? I have found maximum torque with MBT occurs around 12.9AFR. The only time I aim for AFR>13.5 is low manifold pressures and low RPM.

What kind of injectors are you running? and what kind of FPW are you seeing?

Also resonance plays a huge part in power. Our intake is tuned to use a second fundamental frequency at 10500RPM so it sustains our torque curve at high RPMs. With that short of primaries on your dyno exhaust I would be expecting a very high natural resonance but you may be using your second or third set of pressure waves during a lower fundamental which may be contributing to a lower power output.

Does your ECU allow real time tuning? im not familiar with the PE units as we use a TEC3 but if you can real time tune with the engine running I suggest using a potentiometer for fuel and spark so that you can dynamically change them at steady state without having to enter in values over and over. We do this and it has made a huge difference in our tuning time and precision.

[Tom Holdstock]

Hi Dallas,

I've only really started testing this week so i went for 14.7 to start to see the improvement sover richening the mixture.

It is a wide band LM-1 air fuel merer placed one meter down from the collector.


The ECU allows real time changes, so as i oncrease load and the pressure increases i can ut the numbersa in to fit each load and rpm settinng.

Unfortubnately the person last year built the rig on his own so didn't have the time to tune the intake and exhaust and my project only covers tuning the ECU. I'm getting the team to tune the ntake and exhaust for the comp thio, your suggestion of a tuned length of 10,5000rpm sounds good to sustaon the high torque curve.

The iunjectors are 135cc/m3 or around 8lbd'per hour i think, don't have a converter infornt of me.

I'm gonna richen it in stages and get power curves for each AFR and use the AFR that produceds the best power for that rpm. Seems the simplest way to go. Then when our rae engine gets installed with exhast and intake set up we should see and even bigger increases in power. If you have any more suggestions fire away. We can only adapt fuel delivery amount and ignition timing, and other compensation factors but they aren't that important except for the accelaration compensation... how did you set that?


one more thing... did you go leaner than 14.7 afr for the endurance event?

[Dallas Blake]

Tom,

What kind of aceleration enrichments are there? We use TPS rate of change and MAP rate of change and get the driver to take a corner and hit full throttle corner exit, then view the datalog to see %FPW and AFR during the TPS change

[Garlic]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Tom Holdstock:
cheers, dallas

Thats apporx 10 degrees more on each than i'm using... I'll put those numbers in or iterate up to them and see what I get...

I'm on 51hp witha 14.7afr and around 35 ilft torque but i expect these to go up with an increased fuel ratio... i'm iterating the air fule ratio to get the optimum power. The main problem is the header i have on the rig, oit collets just after the head and restricts the flow a bit... there'll be a 4-2-1 for the cmop which will increase the power too.

Check the heat on this:

http://i70.photobucket.com/albums/i119/moscoworbust/DSC00738.jpg </div></BLOCKQUOTE>

Tuning your engine with an exhaust system like that is a COMPLETE waste of time.

You need to do your dyno tuning with something at least approaching realsitic exhaust. Ideally, you will use the exhaust that will be run on the car.

[Bill Kunst]

Not only do I cringe at the thought that you are running 14.7afr, but the question of running leaner then that scares the shit right out of me. I am currently cleaning my seat. Dyno loading can be a vary touchy issue. If you are loading the engine and not accelerating it, you will definitely end up causing damage with those afr's. Listen to dallas blake and get that into the 12's.

As for the "collector": I wonder where all the heat is from?! Without a smooth flow of the exhaust at a high rate of spped through the header, you will definitely be heat soaking. Stagnate gases around 1400 degrees will do that to an exhaust. I don't even need to see your egt's to tell that they are over 1375-1400. Get a real header, ss headers sells them and supplies to make them at a reasonable price.
Bill

[Grant Mahler]

I totally agree with Bill Kunst.

I would strongly suggest that you stop, and turn everything off. Not to be an ass, but you need to learn more before you should be allowed on the dyno. You could really hurt someone with EGTs and AFRs like that. The motor WILL grenade, and I hope noone is nearby.

Change the exhaust, add some fuel, read the forums, buy and read Taylor's book, and then go back to the dyno.

[BrendonD]

Ditch the intake manifold... it serves no purpose on that side of the combustion chamber.

[Dallas Blake]

Whats been said above is correct. You really need to tune with what is going to be on the car. Because resonance and flow differences between cylinders play a huge part in power output and subsequently fuel consumption in our competition you need to make the final product or something that will be close before you tune your engine.

Also, you need to have EGT on each of your runners to properly monitor temperature. With one EGT in the collector you are not getting an accurate idea of the individual running condition of each of the cylinders.

[Beatle]

To echo what has already been said, get your lambda to around 0.85-0.87 for high load, and advance your spark. These engines rev so high and have such high burn rates that detonation is not a huge concern for anything above 9k. You can run what would normally be an insane amount of spark at high RPM (by that I mean in the high 50's), my team has been doing it for years, and we have never knocked (F4i, not F3, but they are essentially the same). Your egts should not exceed 725 C with an NA setup. These exhuast valves should not be exposed to more than 750 C for more than a minute or so.
Also, everyone here is right, you need to tune with the parts that are going on your car. Resonances can have a very noticable impact on fuel and spark maps, as well as on egts (plural because you need probes in each runner, and you need them about 1-2 inches from the port).

[Bill Kunst]

What is going on with the engine???? Hope everything is okay,
Bill

[Tom Holdstock]

Hi Bill,
I'm working on it as we speak. I did hte first run on 14.7 AFR to show the different effects of different AFRs, as this is a dissertation into the effects of the ecu and not to just get max power out of the engine. I was also only enquiring if anyone had gone leaner than 14.7 to see the effects. I guess no one has tried, i'm not going too.

I'm currntly reducing the afrs to see there effect on the torque and power outpts, imm now into the 12's and getting more power lowr down the rev range. he ignition is currently quite retarded, max 35 degrees but i think this is safe to starts and when i've decided on a set of AFrs for the rev range then i wil advamce it in stages to see the effect of that.

The exhaust. I've been watching the EGT's and although the collector is glowing red hot at high rpms undder load the temp is not going up to 900 which is good.
The header is going ot have tos tay as it is, my lectureer says that as we can;t get the exhaust which is going on the bike on the dyno due to safety reasons (extractuion of gases) and it isn't even built. It is our first year. The plenum is the best alternative. Although i'll keep on at them. The main thing is that all factors such as exhaust and uintake are constant through out my project. We might not even get into class 1 this year so people wil wrk on what i've done and written next year.

I'm getting temp gauges put on each port for next year.

Thsnks for all the advice, i'll keep you posted.

Is anyone tunnig intake lengths, above the throttle body?

Good news is that our race motor has now ben built and is getting put on the dyno next week. Fully ported, lightly polished, highest compression we could go on pump gas, blue printed, and full race cams. Lovely. The engine has a couple of lap records from when i was in a bike around the uk circuits!

The acceleration compensation i was asking about was for throttle accelration, just wondering ifg anyone had set it properly as i don't have time to work it out on the dyno. But as matey said it needs to be set whilst driving the car.

So far max power 52bhp
max torque 33 lbs ft,

the only way is up.....

[Grant Mahler]

What grade and material is your exhaust plenum/manifold?

Pretty much the only situation I can think of where it is OK to go leaner than 14.7 is on a street car on off throttle cruise, or no load at a specific RPM. Sometimes people will go up to something like 15.3 or so. Minimal gains if you ask me (they are only doing this for efficiency as far as I know). As everyone has said, stoich at anything other than idle is suicidal.

The reason your EGTs are so low is your sensor is pretty far back and in a poor location to measure EGTs. Take a look at your exhaust from a fluids point of view. Take a look at how people build intakes. One (of many) purposes of the intake manifold is to provide a constant source of air - this means a (relatively) slow-moving reserve of air. The opposite is true of exhuast - you want that hot air out of there, and timed so that each pulse will pull out the next pulse. You have done the opposite - you have stagnated the exhaust gases. And you have put your sensor in a place that wont get much flow.

My suggestion, if you are stuck using that exhaust manifold, is to put some bungs in the exhaust runners and try putting your sensor in each runner - see what happens. Leave it measuring the hottest cylinder.

35* advance is a little low in my opinion, but I've no experience with your setup specifically. I have seen people run not enough advance, and hot exhausts (like yours) and have enough fuel in the mixture to blow up their exhaust. Not pretty, and not safe. Just keep that in mind. Less advance is not always safer - the combustion process may not finish fast enough, especially at high RPM, and you may get a fireball big enough to blow things up.

I would almost say that any results you get with this exhaust setup should be thrown out. It *may* be possible to generate some trend lines with it in place, but the absolute numbers will be horribly inaccurate. You may get some wrong impressions as to how much advance and fuel you can run b/c the exhaust is so ridiculously poor. You have taken a motor that expects to run 5 strokes, and is only getting 4. You are completely destroying the scavenging effects that *can* make a huge difference on a motor as advanced as an F3.

I would really suggest sitting down with someone who does this for a living, and having them look over your shoulder for a couple hours. It helped me enormously, and I think it is a good idea from a safety point of view. You seem to have just enough knowledge to be really dangerous. You really should pick up some tuning theory books so that you understand more of what is going on.

But this is all just my opinion. Take it or leave it.

[Tom Holdstock]

ok.

firstly, nothing will blow up. only iraq.

second, what kind of increase in bhp will i actually get with the right exhaust? 5-10%,. fine, but my project is lookinginto the effects of tuning with an ecu with this set up so it is irrelevant.

the advance i have is safe for preliminary testing into different AFR's. Advancing it too much would be the problem leading to detonation, etc.

Your commenst are noted, basically we'll build a header into the dyno for next year and put some temp gauges in..

[Bill Kunst]

Just a few notes on this topic that may help other teams as well.

From the stand point of ignition advance. If you run very little, blowing up the exhaust is the least of the worries. Temps during the flame front are extreme, and with correct timing, the exhaust valve reflects that back to the combustion event. With retarded timing, the flame front is moving as the valve opens and causes extreme heat transfer and erosion to the valve, head, and seat. This can lead to cracking of valves, and other problems.

As for the plenum exhaust. Without proper scavenging through a 4-2-1 or 4-1 header, your afr's will be horribly wrong when it comes time to put on the correct header. The reason for this is the scavenging and cross flow of the two latter stated designs will far exceed the plenums and will draw in more intake charge as a result of the overlap of the valves. More air, same fuel, lean mixture. You may say that the computer will compensate for increase in vacuum, but the problem becomes that you are missing a part of the graph as the vacuum levels were never there before.


Oh yeah, Grant: It's a four stroke, not a five. Let me know when you bring the five stroke engine out, I want to see it http://fsae.com/groupee_common/emoticons/icon_wink.gif http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Grant Mahler]

Bill - you got me. I was referring to scavenging, but you are correct.

[Rex Chan]

Sorry guy to bring up an old thread, but its the one with the most relevant info for the questions I'll be asking.

Short version: we just tuned a whole fuel map with values that directly contradict what was posted above. Nothing bad has happened yet. So I suppose my question is: should I be worried, and what are the current values people are using to guide their tuning?

Long version (and yes, it will be very long):

Background: we run a NA CBR600RR 03-06, with aluminium cylinder intake and 4-1 exhaust (so not the manifold thing in the photo above). Pretty standard stuff. We're running E85 (RaceFuels E85, which is guaranteed to be 85% ethanol and 15% 98RON).

Due to ethanol in our oil issues and lots of points for fuel economy this year, we run lean.

We tune on a eddy current steady state dyno. Torque values are from a load cell loaded directly from the dyno. We measure lambda in the secondary, just after the collector, with a MoTeC PLM and a Bosch LSU 4.0.

EGT's are measured for all 4 cylinders, about 1-1.5" after the exhaust port. So they're pretty close to the exhaust valves. Running regular K-type thermocouples, into the dyno controller. probably an Omron t/c amp of some sort.

Running a MoTeC m400 and PDM15 and Bosch 4-channel ign module. Efficiency is based on MAP (not TPS).

I will be using lambda/LA (rather than AFR). it's just what we got taught in class, and makes comparing between gasoline and e85 easier.

Values we tuned for and observed: we aimed for LA=0.90 at WOT/100kPa. Our EGT's were around low 700C to high 700C, but I didn't see it ever go into the 800C. This was at 10k-12k. Even at 6k though, we were getting 650C EGTs. The exhaust tubes (1.6mm wall/31.8mmOD) changed from shiny raw steel to rusty/gray crappy color, but no glowing red tubes.

Although we aimed for LA=0.90 at 100kPa, we were at LA=1.00 at around 75kPa, and LA=1.10-1.15 at 60kPa.

We ran these values for 10-20 minutes at a time, so spent quite a long time under load. I did a leakdown test today, after all the fuel map tuning, and got 82-88/90psi. Pretty much what we had before starting to tune, and pretty good values too. So that seems ok.

My current understanding is that we run rich at WOT to keep the gasses cool, and prevent knocking. Does this mean we can run leaner if we don't have issues with either?

Before reading the above posts, I thought that sub-800C EGTs were quite ok, so we had room to go hotter. I don't have any way to determine knock, but a) we're running e85, which has an RON of 107 and b) in 2009, they ran 10-20 degrees more advance than we currently run, and no motor failures were attributed to knock (they killed an engine with too much ethanol in oil&gt;lack of cylinder lube&gt;scuffing bores). Now I'm uncertain again.

Running AFR of 12:1 = LA=0.82, which means 20% extra fuel is going somewhere; some into the oil. That's why we run LA=0.9-as lean as possible while still getting combustion: to avoid excess fuel floating around the combustion chamber.

Why is there a 750C limit on EGT's? Is a material limit of the Honda CBR600RR exhaust valves? Does anyone know what they're made of?

Re: Grant Mahler - we ran the 2010 engine at LA=1.4 at idle (2400rpm/75kPa), and have idled the 2011 engine on the dyno at 1000RPM/100kPa at LA=1.8. But EGT was below 200C, so LSU was too cold for correct reading.

Last thing: we will be doing lambda sweeps at WOT (going from LA=0.85 to LA=1.05), to see the effect of fuel economy vs torque. We've done 5k and 7k so far, and no rise in EGTs.

Note on AT/ET/OilT: manifold air temps were max 30C, ET is too cool at 75C, and Oil temps get up to 130/140C before the PDM shuts it all down. We change the oil every hour of run time though, or if we've run it hard, or if it starts to go dark. We have Valvoline as an awesome oil sponsor who lets us do this (fully synthetic SynPower 5W-40). Water temps are independent of oil temps due to separate cooling lines/pumps.

[Rex Chan]

Another small thing - I've got lots of YouTube videos of the dyno setup, so click on the link in my sig to get a feel of how we're set up (measuring devices, exhaust layout, etc)

[Mbirt]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Rex Chan:
My current understanding is that we run rich at WOT to keep the gasses cool, and prevent knocking. Does this mean we can run leaner if we don't have issues with either?

Running AFR of 12:1 = LA=0.82, which means 20% extra fuel is going somewhere; some into the oil. That's why we run LA=0.9-as lean as possible while still getting combustion: to avoid excess fuel floating around the combustion chamber.
</div></BLOCKQUOTE>To my knowledge, LBT is always rich of stoich because you can't possibly vaporize all of the inducted fuel for combustion. If no fuel is detected by the lambda sensor, not all available oxygen is being combusted for glorious IMEP. Sorry if that sounded insultingly elementary, but Blair digs deeper into it in "Design and Simulation".

IIRC, RBT for E85 is close to 0.7 lambda. I've never seen an asterisk stating that running RBT at WOT will wash your cylinder walls. In FSAE, to me at least, the greatest risk for washing cylinder walls is while cranking.

[pheyden]

Hello Tom,

My name is Paul and I have been tuning motors for the last 35 odd years (showing my age).

It is my view that you need to do a LOT more reading about air/fuel ratios, resonant tuning, scavenging etc etc. BEFORE subjecting some poor unsuspecting engine to your tuning abuse.

Running almost anything at 14.7 AFR, without some type of closed loop control, is just plain silly. You use 14.7 if you are trying to win an economy run only, and then only in flat level ground, with low ambient temperatures etc etc.

On my own engine dyno I always take notice if the A/F ratio get anywhere north of 13:1.

Of course I may have it all wrong, and have been living some type of illusion for the last 35 years. I may not have all the book-learning, but I know what causes motors to go "boom".

Paul
www.scuderiatopolino.com (http://www.scuderiatopolino.com)

[Mbirt]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by pheyden:
Running almost anything at 14.7 AFR, without some type of closed loop control, is just plain silly. You use 14.7 if you are trying to win an economy run only, and then only in flat level ground, with low ambient temperatures etc etc.
</div></BLOCKQUOTE>Great to have you on the forum, Paul! Hope you stick around and share more of your experience with us. Did you ever get a chance to check out the FSAE competition at VIR in 2008 and 2009?

About fuel economy, many teams are developing EFI calibrations just for that. At the US competitions, fuel usage during our 22 km "endurance" event is worth 100 points. The endurance itself is 300 points, while autocross is 150, acceleration (timed 75 m drag trial) is 75 points, and skidpad (50 ft dia, average of best time CW and CCW) is 50 points. The team that ran the fastest lap times by a significant margin at Formula Student Germany 2011 did so with a claimed 42 hp. So, as long as the car is drivable and the motor holds together for the length of the endurance event, most of us are willing to sacrifice peak power for fuel usage.

Another thing is that the 20mm intake restrictor effectively throttles some of the motors used in FSAE. If MAP only reads 90 kPa or so at WOT, running leaner than an unrestricted engine makes even more sense.